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Finding the Fourth Proportional to 306.48, 422.40 and 290.07

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Solution

The fourth proportional to 306.48, 422.40 and 290.07 is: 399.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.48 : 422.40 = 290.07 : x
  2. Step 2: Convert to fraction form
    306.48/422.40 = 290.07/x
  3. Step 3: Cross multiply
    306.48x = 422.40 × 290.07
  4. Step 4: Simplify right side
    306.48x = 122,525.57
  5. Step 5: Solve for x
    x = 122,525.57/306.48
  6. Step 6: Final answer
    x = 399.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.